Ctrl-e can only host specific synths of curated Expressive E partners and Expressive E's own MPE instruments like Noisy 2 or the Soliste suite.

When you own one of those synths, automatically detects the VST3 version of supported instruments when you launch it. Ctrl-e's menu allows opening its VST manager to see which instruments currently run as engine-only versions without graphical user interface, and which instruments are available as full version with full editing access.